<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8" />
    <meta
      name="viewport"
      content="width=device-width,initial-scale=1,maximum-scale=1,user-scalable=no"
    />

    <title>滚动渐变导航栏</title>
    <link rel="stylesheet" href="index.css" />

    <link rel="icon" type="image/x-icon" href="../../../favicon.ico" />
</head>

  <body>
    <header>
      <a href="#" class="logo">logo</a>
      <ul>
        <li><a href="#">探索车型</a></li>
        <li><a href="#">官方商城</a></li>
        <li><a href="#">车主服务</a></li>
        <li><a href="#">科技创新</a></li>
        <li><a href="#">奔驰天下</a></li>
        <li><a href="#">预约品鉴</a></li>
      </ul>
    </header>
    <section class="banner1"></section>
    <section class="banner2"></section>
    <script>
      // 鼠标滚轮滚动事件
      window.addEventListener("scroll", () => {
        let header = document.querySelector("header");
        header.classList.toggle("sticky", window.scrollY > 0);
      });
    </script>
  </body>
</html>
